how to generate a random character in swift code example

Example 1: swift generate random number

let randomInt = Int.random(in: 0..<6)
let randomDouble = Double.random(in: 2.71828...3.14159)
let randomBool = Bool.random()

Example 2: random string swift

func randomString(of length: Int) -> String {
    let letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
    var s = ""
    for _ in 0 ..< length {
        s.append(letters.randomElement()!)
    }
    return s
}